The Mass Spectrometry Facility provides analytical methods to Kaplan Comprehensive Cancer Center members for the determination of chemical structure, molecular weight and elemental composition of purified synthetic or isolated compounds. The Facility employs gas chromatography (GC) coupled to mass spectrometry (MS) to separate and identify components in complex mixtures. The unit uses GC/MS In cancer-related projects to identify tumor promoters and potential activated carcinogenic intermediates. The focus of the resource has been on the chemical characterization of DNA modified by the direct-acting alkylating and acylating mutagens and carcinogens.